Composite reenforced paper fabric



Dec. 31, 1935. E. c. SMITH 2,026,194

COMPOSITE REENEORCED PAPER FABRIC Fi led June 29, 1954 7 2 sheets-shawlINVENTOR. W CM. BY 412% ATTORNEY 2 Sheets-Sheet 2 Filed June 29, 1954INVENTOR.

ATTORNE Y Patented D. 31, 1935 Edward C. Smith, Nashua, N. AmericanReenforced Paper H., assignor to Company, Att-leboro, Mass a corporationof Massachusetts Application June 29, 1934, Serial No. 732,969 4 Claims.(01. 229-49) This invention relates to composite reenforced paperfabrics and the method of making the same, and is more particularlyconcerned in the production of such a structure that will be generallyuseful throughout a wide range of purposes, and especially well adaptedfor box corner stay strips. The invention will, therefore, be describedin connection with box corner stay strips although it is not to beunderstood that the invention is restricted thereto.

It is now the usual practice to apply box corner stay strips to boxcorners to impart strength thereto or to the box as a whole, and suchstrips have been variously formed. In some instances they have consistedof a strip of woven material pasted or otherwise secured to the sides ofa box to extend over the corner thereof. It has likewise been proposedto use paper as a stay strip in either a single or composite layers, butwhere it is formed of a single layer, its inherent weakness renders itunsatisfactory. And where layers of paper have been tried it is foundthat the layers separate and become broken when the box is set up byreason of the tension mainly manifestecl on the exterior paper layer.

One of the objects of the present invention is to provide a which, whilegenerally useful for many purposes, lends itself advantageously to theformation of box corner stay strips, and the invention will, therefore,be described in this connection.

In accordance with the present invention the layers of material whichconstitute the composite fabric are secured together face to face by anadhesive which may be of a waterproof character such as asphaltum, andreenforcing unspun fibres are embedded in the adhesive between thelayers of the completed fabric.

When the fabric is to be used as a box corner stay strip the exteriorsurface'of one of the layers of material is supplied with a gum whichmay extend as a continuous coating or arranged as a pattern with blankor ungummed portions, and in order to dry the gum the fabric, as thusfar described, is subjected to a drying heat which may be in theneighborhood of 180 F. The drying heat is liable to so far soften theadhesive between the layers that the layers may separate at certainpoints due to shrinkage or the like, and when the fabric is bent as inthe application to the corners of a box, this separation may become moremarked by reason of the tension exerted upon the outer layer which, ofcourse, occupies a more extended arc than does the inner layer.

composite reenforced paper fabric,

It is,- therefore, one of the objects of the present invention to impartto the outer layer of the composite fabric the capacity for yielding inthe direction of the bend, thereby eliminating the surface tension andpermitting the-layers of material to remain in close union under theaction of the adhesive.

The invention and novel features thereof will best be made clear fromthe following description and accompanying drawings of one method andconstruction for attaining the objects sought.

In the drawings:-

Fig. 1 represents a roll of two ply fabric reenforced transversely byunspun fibres and secured together byan adhesive such as asphaltum.

Fig. 2 shows one means of imparting to the ungummed layer an embossedcondition by indentations impressed into the body of the outer layer;

Fig. 3 shows the manner of slitting the fabric in the formation of a boxcorner stay strip;

Fig. 4 is an enlarged and much exaggerated. sectional view on the line4-4 of Fig. 3;

Fig. 5 is a perspective view showing the box corner stay strip as havingbeen applied to the box corner, a portion of the upper layer beingturned back to show the construction beneath;

Fig. 6 represents a diagrammatic view of a box corner with a stay stripassociated therewith; and

Fig. 7 is a perspective view showing a portion of a box, the two cornersof which are strengthened by the box corner stay strip Referring moreparticularly to Fig. l the paper roll i commonly referred to as a jumboroll has wound thereon a composite reenforced fabric A, comprising theupper layer 2 which is turned back to disclose the adhesive and embeddedunspun fibres 3 which, in this instance, extend transversely to thelengthwise dimension of the composite fabric, it being supposed, asshown, that the final product is to be cut lengthwise into numerousstrips. If, however, the final product, as will be hereinafterdescribed, is to be cut transversely, then the unspun fibres may extendlongitudinallyv As the composite fabric A is taken from the jumbo roll Ithe under layer is supplied with a gum, as indicated by the stippleportion 4. The

gum is usually applied in a liquid or semi-liquid 5 state and the nowgummed reenforced fabric is subjected to a drying temperature to dry andset the gum and when so dried or set the composite fabric may again berolled up into a second jumbo roll 5. This is possible because the gumhas been III duly dried and preferably at approximately a temperature ofF.

The composite fabric 8 on the jumbo roll 5 now consists of superposedlayers of sheet material, one at least' of which shall be paper, and theunder layer as above explained with respect to Fig. 1 is provided with adried gummed surface 4.

In order that the upper or ungummed layer may be given its desiredcharacteristic of expansibility or elimination ofsurface tension, thecomposite fabric 6, Fig. 2, has the upper layer thereof embossed orindented. The embossed or indented effect may be imparted to the upperungummed paper layer by subjecting the composite fabric to the pressureof an embossing element.

The embossing elements in the illustrated form of the inventioncomprises the under or smooth presser roll I and the upper or embossingroll 8 between which the composite paper fabric is passed, as indicatedin Fig. 2, the effect being that the upper layer of fabric is embossedor indented and the pressure of the rolls I and 8 will have the effectof reuniting the two layers should they have become separated during thegumming and drying process.

The composite fabric 6 as hereinbefore noted, has the under layer nowprovided with a dried or set gum 4, while the upper layer of thecomposite fabric 6 is untreated. As the fabric 6 passes between the tworolls I and 8 the upper layer of paper fabric is provided withindentations 9 which may generally be described as an embossedcondition.

The embossing designs or indentations are not deep but penetrate aboutone-half the depth of the top sheet of paper or kraft and are justsufficient to remove surface tension from this sheet. This is indicatedin a somewhat exaggerated. form in Fig. 4 wherein it will be noted thatthe top sheet is embossed or indented as at a only to such an extent asto not materially disturb the unspun reenforcing filaments 3. Theembossed efiect does not pass through the entire composite fabric but,as noted, is only sufficiently deep to impart to the top sheet acharacter of expansibility and relieve tension to the paper layer whenthe composite sheet is bent around an object. The embossing design maybe of any desired character, but as shown in the present instance of theinvention, the embossing design 9 extends longitudinally of the uppersheet.

When a box corner is to be strengthened by the stay strip, the box IIIis in a knock-down condition, as indicated in Fig. 5, and the stay stripis adhesively connected to adjacent portions of the box at each side ofthe bend, with the result that when the box is set up, as indicated inFigs. 6 and 'l, the portion of the stay strip next to the box occupies aless distance or arc, if it may be called so, than does the outer orupper layer of paper. This, of course, imparts a strain upon the upperlayer but the embossed condition thereof permits the surface tension tobe relieved.

The box comer stay strip may be generally identified as B, as indicatedin Figs. 5, 6 and 7, and such stay strip is cut from the gummed andembossed composite fabric as it is drawn from the jumbo roll C, asindicated more clearly in Fig. 3, where only one strip is shown as beingcut from the f nished composite fabric, but it will be understood thatthe entire width of the composite fabric may be formed into stripssimilar to that indicated at B, Fig. 3.

From the construction described it will be apparent that the presentinvention provides a 5 reenforced composite paper fabric wherein theexterior surface of one of the layers is gummed and dried and thesuperposed layer is embossed or indented to relieve surface tension.Obviously the character of the embossing effect may be n varied betweenwide limits, the purpose being in any case to relieve the top paperlayer from undue or disturbing tension when the gummed and embossedfabric is bent around an object to which it is to be attached. 1:;

Usually the stay strip will be applied only on the joint or corner wherethe two ends of the box blank abut or come together, but, as indicatedin Fig. 7, the stay strip may also be applied at other comers of the boxstructure if desired. 20

In the embossing operation, it is possible that the use of an underembossing roll instead of the plain roll, as shown, might beadvantageously employed, but as this is an obvious condition it is notillustrated. as

What is claimed is:-

1. As an article of manufacture, a. composite reenforced paper fabric,comprising two paper sheets secured together face to face by an adhesiveand reenforcing unspun fibres embedded 30 in the adhesive between thesheets, one of the paper sheets having a gummed exterior surface, andthe body of the other paper sheet being embossed or indented to renderit flexible and relieve tension without rupturing when the com- 35posite paper fabric is bent about an object.

2. As an article of manufacture, a composite reenforced paper fabric forbox corner stay strips, comprising a layer of sheet material having agummed surface, another paper strip or'40 sheet embossed or indented torelieve tension therein and prevent rupturing when the composite fabricis bent about the corner of a box, an adhesive for securing the twosheets together face to face, and a series of unspun reenforcing 45filaments held between the two sheets by the adhesive.

3. As an article of manufacture, a composite reenforced paper fabric forbox corner stay strips, comprising a layer of sheet material hav- 50 inga gummed surface, another paper strip or sheet embossed or indented torelieve .tension therein and prevent rupturing when the composite fabricis bent about the corner of a box, an adhesive for securing the twosheets to- 55 gether face to face, and a series of unspun reenforcingfilaments extending transversely of the composite fabric and heldbetween the sheets by the adhesive.

4. A composite reenforced box corner stay 60 strip, comprising twolayers or strips of paper secured together face to face by an adhesiveand reenforcing unspun fibres extending transversely of and between thetwo layers or strips of paper and held in place by the adhesive, one 65of the paper layers or strips being provided with a gummed surface forsecuring the stay strip to portions of the box structure, and the otherpaper layer or strip being embossed or indented to relieve surfacetension and prevent rupturing 70 when the stay strip is bent about thecorner of a box.

EDWARD C. SMITH.

